Overview of Game:
The main character of the game is a gum which throws a piece of itself which is called anchor in any direction or at any angle.
There is a thread like connection, which is called connection-thread Object, between the gum and its anchors whose elastic structure is implemented using SpringJoin2D which gives the connection-thread a spring-like behavior.
In order to make the connection-thread more dynamic, a mechanism is added to the game which lets the connection-thread to get segmented by adding a new anchor in the part of the connection-thread that collides with an object in the game environment. In other words whenever an object hits the connection-thread a static anchor is added in the collision point.
The main problem:
The connection-thread Object is scaled and positioned manually in the script, which causes dysfunction in the collision detection system(Box2D) in a way that the collision points cannot be detected correctly.
Used Methods :
boxCollider / EdgeCollider -> dysfunctioned when scaling
RayCast2D / LineCast2D -> middle anchors enter the environment Object in high speed
static boxcollider2D in child object in size of maximum length of connection-thread Object -> [not implemented yet]
Any idea to fix this ?
As far as i know, with kinematic objects you can only have trigger events which only return colliders and not collision information.
I think you may try to check the collision with triggers and then do a circle sweep test in 8 direction for example to search for a collision and receive the information with the raycasthit2D. The sweep test will return you a raycasthit2D wich have a "point" member you can use.
Follow this links -
Unity Manual
http://docs.unity3d.com/ScriptReference/Physics2D.CircleCast.html
How Capsule and Sphere Cast work (same thing as circle cast but in 3D)
https://www.youtube.com/watch?v=D1xqen8uH64
Hope I could explain myself well enough. Good luck
Related
I recently started having a look at game development with Unity and was trying to make a simple 2D character with basic movement abilities. This character is supposed to jump and move from side to side, but only if it is standing on something.
Now my question is: How do you check if a player is standing on something? / Get the distance to the next game object / collider beneath the player game object?
Would greatly apreciate any helpful answers and especially explanations on how exactly it works. Thanks!
To do this, you need to send a ray to detect the point of impact on the ground and then calculate the distance. The code below sends a ray from the center of your object down to the maximum height (3) and gives the size.
public LayerMask groundLayer;
public float maxRayLength = 3;
public void Update()
{
var hit = Physics2D.Raycast(transform.position, Vector3.down, maxRayLength, groundLayer.value);
if (hit) Debug.Log(hit.distance); // it will print current distance from pivot
}
If you want to calculate the height of the ray from the character's foot, there are two methods, one is subtracting half the height of the character from it.
Physics2D.Raycast(transform.position-transform.up*height, ....)
Next one is to use an empty object at the base of the character, which we refer to instead of the center.
public Transform pivot;
Then..
Physics2D.Raycast(pivot, ....)
There are a few ways of actually doing this.
The most usual although a bit complicated way of doing it for a beginner is using Raycasts. A Raycast is basically a small invisible line that starts and ends where you tell it to. If anything of a specific tag or layer is caught in it's crossfire you can basically pull that object from your code. Raycasts are used for a lot of things, most notably in Shooter games to shoot or in games like Skyrim to pickup objects and interact with them.
Another way to do this, which is a bit more popular in 2D games is to create a "feet" GameObject and make it the child of the player in the hierarchy. You can add a box collider on that GameObject and check the "IsTrigger". You can add a Tag to your ground objects and through your code using the OnTriggerEnter() and OnTriggerExit() Methods you can basically tell when your character is floating on air and when he is on ground.
Another popular method is to use the Physics.OverlapBox() Method which is pretty much the same as the Trigger Method but you are creating an invisible box (much like a raycast) and instead of only getting notified when Triggered (something enters or exits) you check if the invisible box is colliding with another object/tag/collider (which could be your ground).
There are also a few different things you can do with a Nav Mesh (mostly in 3D) but I think that for now these 3 should suffice!
I have a sphere collider on a stick and a cylinder. The cylinder has to detect a collision with the sphere collider of the stick and fire up a "OnTriggerEnter" script. Just imagine it like a drum stick hitting a drum in virtual reality.
Is there a way to avoid registering a collision on the sides of the cylinder, but only trigger on the top of the cylinder? And even without adding more protecting objects around it?
In the screenshot you see the properties of the stick and below the properties of the cylinder.
Obviously the green and red icons show which area is allowed to be triggered and which not.
Btw, simply using a thinner cylinder collider doesn't work in this case, because it wouldn't detect some collisions at all, when the stick goes too fast trough the thin cylinder. More about that in the comments.
Thank you.
Hi guys i was wondering how to create a shape adjustment with two objects which specifically could be described as the independent cells, one of which is static, and the second one is dynamic and surrounded by "plasma". The movement of the active object must be controllable by the user (WSAD). Collision of the active object with the static one causes the static object to be swallen, though doesn't change it's position stays in place all the time. As the active object moves, passes the swallen object and troughts it out.
See the image below:
Player character
When it comes close enough to pink enemy it's starting to swallow it (surround by yellow thing)
Pink enemy is completely sourrounded when red circle is in the centre of both.
When it leaves enemy it takes off the yellow thing
I was wondering what is the simplest way to do it. I've been thinking about cloth, physics joints, mesh substraction (is it even possible?), some kind of animation... I don't have much time to do it. Can you show me the simplest way. Which tools and approach should i use? I'm not asking for full code or full solution only for some tips.
Tim Hunter mentioned a wonderful way, most perfect in 3D.
You can use another approach in 2D :
Inside OnCollisionEnter2D try finding hit points using Collision2D.contacts . See this reference .
Create some particle effect there.
Disable the enemy
Now play swallowing animation of the player.
At animation end, enable enemy again.
Maybe calculation is little tricky, still efficient.
I have 5 gameobjects on my scene, all having a collider attached to it.
Now I don't know why - but my first top layer (a starBtn) sometimes fail to detect a mouseClick?
It's in 2d.
I detect all raycastHits and store the hits in an array - I then check all layers of all of them and return the one at the top layer. The one I need to call anaction/function from. My top layer is a square sprite.
Is there a best practice for this or a way to ingnore a collider area if an object in from of it is overlapping?
Cheers
Ps: I willadd code to this question in an hour or so.
Ok. What I had to do to solve this was to add a z-value to each object with a collider.
Then cycle through each objects' z-value - storing the highest value. Although this is 2d.
I have an object which has a diffuse shader and on runtime I want the shader to switch to Diffuse Always Visible but this should trigger only if the unit is behind a specific object within the layer named obstacles.
First I tried to switch the object shader with the following code and the shader is changed in the inspector but not in the game during play. I tried placing and calling the shader from the resources and also created seprate materials but its not working.
Here is the code I am using in C#
Unit.renderer.material.shader = Shader.Find("Diffuse - Always visible");
As for the rest I was thinking of using a raycast but not sure how to handle this.
Thanks in advance
I only need the other concept now where the shader changes if a unit is behind an object!
For the trigger, how to handle it will depend a lot on how your camera moves.
To check in a 3D game, raycasts should work. Because whether or not something is "behind" something else depends on the camera's perspective, I would personally try something like this to start:
Use Camera.WorldToScreenPoint to figure out where your object is on the screen.
Use Camera.ScreenPointToRay to convert this into a ray you'll send through the physics engine.
Use Physics.Raycast and check what gets hit. If it doesn't hit the object in question, something is in front of it.
Depending on your goals, you might want to check different points. If you're just checking if something is more than halfway covered by an object, doing a single raycast at its center is probably sufficient. If you want to see if it's at all occluded, you could try something like finding four approximate corners of the object and raycasting against them.
If it's a 2D game or the camera is always at a fixed angle (for example, in a side scroller), the problem is potentially a lot simpler. Add colliders to the objects, and use OnTriggerEnter or OnTriggerEnter2D (along with the corresponding Exit functions). That only works if the tiniest bit of overlap should trigger the effect, and it only works if depth doesn't really matter (e.g. in a 2D game) so your colliders will actually intersect.